the coil does effect this but there's also a lot of different sources also. Have you checked your wires/wire ends,cap, rotor,etc? I've also had this problem and just changed my coil this past weekend (just because I noticed on the paperwork that came with the car that a previous printout from a service done on it noted that the coil was "weak" and had a slight miss/bump at idle) and it smoothed out and throttle response was great initially up until like Tuesday when it went back to its old ways. It then ran perfectly again for another couple of days until it kinda resembled the symptoms a little bit this morning. I'm also gonna replace my new wires when they get here and my cap, rotor and see what happens. Good Luck
Alan
P.S. My search for a new bosch coil found fluctuations in price from about $115.00 at some places up to over $200 at the Dealer. I ended up with a great deal from N.O.P.I. aouto parts store here in Atlanta who ordered the same coil directly from bosch for $80 and just charged me $4 for the shipping in 2 days! So shop around
